6 Farmers’ Bulletin 1197. 
INSECTS RESPONSIBLE FOR THE DAMAGE. 
Although many different insects feed in the mesquite, not more 
than five or six are responsible for most of the injury in any locality, 
being numerically the more abundant or causing the greater damage 
by the character of their work.’ 
These insects, according to their structure and the character of 
their work, may be grouped into three types or classes—namely, 
roundheaded borers, powder-post beetles, and flat-headed beetles. In 
the vicinity of Tucson, Ariz.,' where the experiments were conducted 
on which the results of this paper are based, there is only one round- 
Vig. 5.—Adult beetle of the roundheaded borer in mesquite. 
Enlarged. 
headed borer? of much economic importance, but this is the most 
destructive insect in mesquite. Three powder-post beetles are found, 
a large? a medium,‘ and a small® form. One flat-headed borer ® has 
been found to cause considerable injury. 
CHARACTERISTICS OF THE INSECTS AND THEIR WORK. 
All these insects have several distinct forms, known as the egg, the 
larva, the PUDay ou the adult stages, but it is a — larval or 
1In Texas another species of roundheaded borer (Cyllene crinicornis Chey.) and several 
other species of powder-post beetles (Yylobiops spp.) are equally numerous. Their habits 
are much the same and similar methods of treatment are effective. 
2 Cyllene antennatus White (Figs. 3, 5-8.) 
3 Apnatides fortis Lee. (Figs. 9, 12.) 
4 Dendrobiella aspera Lec. (Figs. 4, 11, 15, 14.) 
5 Xylobiops sp. (Figs. 4, 14.) 
6 Chrysobothris octocola Lee. (Figs. 8, 10, 15.) 
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